The blueprint of all living beings is stored in their genetic material. In higher organisms this is stored in the well-protected cell nucleus. "Here a kind of copier works around the clock to make copies of the information needed at the time," says first author Jan Peter Siebrasse from the Institute for Physical and Theoretical Chemistry at the University of Bonn. The copies contain the information which the cells need to produce vital enzymes or other cell building materials. These copies consist of messenger RNA which travels on random paths to the membrane of the cell nucleus and from there through the nuclear pores into the cytoplasm which fills out the cells like jello.
Stringent quality control at the pore
The working group has found out that the messenger RNA lingers briefly at the pores in the membrane of the nucleus before it is finally transported out presumably for a final "quality control" or simply because it has to adjust in order to leave via the pore exit. The export process lasts in total only a few hundredths of a second to several seconds. "In all likelihood, the process needs much longer for larger, voluminous messenger RNA molecules than for smaller ones," adds Prof. Ulrich Kubitscheck, head of the working group Biophysical Chemistry and senior author of the publication.
Interestingly enough, only about every fourth collision between arriving messenger RNA and the cell nucleus leads to a successful export. Here, two kinds of processes can be distinguished: On the one hand, brief collisions with the nuclear membrane where presumably no pore is hit, and, on the other hand, those transports that are slowly aborted perhaps on account of a deficient quality control.
RNA is packed in a suitcase made of "protein"
The RNA is packed in a type of "suitcase" made of proteins for transporting. "And it is quite a chunk," grins Prof. Kubitscheck. This is why some of his colleagues presume ther
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| Contact: Dr. Ulrich Kubitscheck u.kubitscheck@uni-bonn.de 49-228-732-262 University of Bonn Source:Eurekalert |